Inactive fuel passage(s) may be found in equipment for many reasons including, but not limited to: a pilot injector which is utilized for low power operation and may be turned off as required at higher power; staged fuel injector(s) which may be turned on and off based upon desired operating parameters; and/or fuel injectors utilized for operation on different types of fuel at different times. During times that a fuel passage is inoperative, hot combustion products and/or fuel can enter the passages. Also, an inoperative fuel passage for liquid fuel may have stagnant residual fuel that may be altered from exposure to temperature and/or contaminants. Altered stagnant fuel may solidify or otherwise affect the performance of the fuel passage and fuel injector. There is a continued need for a system that minimizes or prevents the introduction of hot combustion products and/or fuel and air into the inactive fuel passage(s) and includes a technique for flushing residual liquid fuel from the inactive fuel passage(s) as disclosed herein.